The present invention relates to a method for laminating plastic films with wood-base substrates, and the products or laminated materials obtainable in this manner, in particular wood-base substrates laminated with plastic films, and the use thereof, in particular in the area of the wood and furniture industry, for example for the production of pieces of furniture and fitments of all kinds.
For the production of high-gloss surfaces on wood-base substrates, in particular board-like wood-base material parts, such as solid wood boards, chipboards or MDF boards (MDF=Medium Density Fiberboard), in particular for purposes of equipping these wood-base substrates with coating and printing materials varying optically and/or haptically on one or both sides, various methods are known from the prior art.
According to conventional methods, for this purpose the wood-base substrate can be provided with a high-gloss surface based on a finish in a multistage work process with complicated staining, grinding and subsequent finishing.
However, particularly in the processing of solvent-containing finishes and printing inks, emissions of volatile organic compounds are an increasing problem for the coating of wood-base materials. In addition, the finishing and printing processes used nowadays give rise to extremely high capital costs and costs for space, energy and operation and for compliance with emissions legislation which increasingly restricts production.
An alternative to the abovementioned multistage staining, grinding and finishing or printing process is the application of a sealing layer to the corresponding wood-base material surface. Thus, for example, WO 02/094457 A2 describes a process and an apparatus for the production of material parts, in particular wood-base material parts, comprising a sealing layer on the surface, this sealing layer being in the form of a water- and solvent-free, polyurethane-based reactive hotmelt layer which cures with atmospheric moisture and is subsequently smoothed with a roll. A disadvantage of this process is the only small variability of the decoration. Furthermore, the sealing layer produced in this manner does not always have the desired evenness or smoothness. Moreover, the sealing layer obtained in this manner does not always meet the desired requirements, in particular with regard to the required abrasion resistance or hardness. Finally, owing to the use of moisture-crosslinking reactive polyurethane hotmelts as coating material, the coating method described in WO 02/094457 A2 permits only low feed speeds because of the initially thermal plastic behavior of the coating material.
The prior art furthermore discloses methods in which plastic sheets or plastic films laminate to the corresponding wood-base materials. Plastic sheets or films suitable for this purpose are sold, for example, by Senoplast Klepsch & Co. GmbH, Piesendorf, Austria. A disadvantage of this method is that only very special plastic sheets or films are used, which are comparatively expensive and are available only in a limited decoration range so that arbitrary individual decorative design is not possible.
It is therefore the object of the present invention to provide a method which is suitable for laminating plastic films with wood-base substrates, in particular for the production of high-gloss surfaces on wood-base substrates, and in particular at least substantially avoids or at least reduces the above-described disadvantages of the prior art.
A further object of the present invention is the provision of a method for coating or laminating wood-base materials or wood-base substrates, in particular board-like wood-base materials, such as solid wood boards, chipboards, MDF boards and the like, with plastic films, in particular for purposes of the production of high-gloss surfaces on wood-base materials or wood-base substrates, and such a method—in comparison with the methods of the prior art—should be much more advantageous in terms of capital costs, energy costs and/or application (costs) and should be of much higher quality and/or much more efficient and flexible in use, should operate very substantially without emission and should therefore be environmentally compatible and in this way should permit novel innovative design possibilities for coatings with plastic films for the producers of articles, in particular from coated wood-base materials.
The object of the present invention is therefore firstly the avoidance or the replacement of complicated staining, grinding and finishing methods by film lamination which is relatively simple to handle and secondly the production of high-gloss surfaces on wood-base materials or wood-base substrates.
The present invention therefore relates—according to a first aspect of the present invention—to a method for laminating a plastic film with a wood-base substrate, in particular for producing a high-gloss surface on a wood-base substrate, in which a plastic film is laminated by means of a laminating agent, preferably an adhesive, with a wood-base substrate and permanently bonded to the wood-base substrate, the plastic film being formed so as to be transparent on its top.